lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 1 Jun 2020 19:54:47 +0200 From: Greg Kroah-Hartman <gregkh@...uxfoundation.org> To: linux-kernel@...r.kernel.org Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, stable@...r.kernel.org, Minh Bùi Quang <minhquangbui99@...il.com>, Björn Töpel <bjorn.topel@...el.com>, Daniel Borkmann <daniel@...earbox.net>, Jonathan Lemon <jonathan.lemon@...il.com> Subject: [PATCH 5.4 129/142] xsk: Add overflow check for u64 division, stored into u32 From: Björn Töpel <bjorn.topel@...el.com> commit b16a87d0aef7a6be766f6618976dc5ff2c689291 upstream. The npgs member of struct xdp_umem is an u32 entity, and stores the number of pages the UMEM consumes. The calculation of npgs npgs = size / PAGE_SIZE can overflow. To avoid overflow scenarios, the division is now first stored in a u64, and the result is verified to fit into 32b. An alternative would be storing the npgs as a u64, however, this wastes memory and is an unrealisticly large packet area. Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Reported-by: "Minh Bùi Quang" <minhquangbui99@...il.com> Signed-off-by: Björn Töpel <bjorn.topel@...el.com> Signed-off-by: Daniel Borkmann <daniel@...earbox.net> Acked-by: Jonathan Lemon <jonathan.lemon@...il.com> Link: https://lore.kernel.org/bpf/CACtPs=GGvV-_Yj6rbpzTVnopgi5nhMoCcTkSkYrJHGQHJWFZMQ@mail.gmail.com/ Link: https://lore.kernel.org/bpf/20200525080400.13195-1-bjorn.topel@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org> --- net/xdp/xdp_umem.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -341,8 +341,8 @@ static int xdp_umem_reg(struct xdp_umem { bool unaligned_chunks = mr->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG; u32 chunk_size = mr->chunk_size, headroom = mr->headroom; + u64 npgs, addr = mr->addr, size = mr->len; unsigned int chunks, chunks_per_page; - u64 addr = mr->addr, size = mr->len; int err; if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE || chunk_size > PAGE_SIZE) { @@ -372,6 +372,10 @@ static int xdp_umem_reg(struct xdp_umem if ((addr + size) < addr) return -EINVAL; + npgs = div_u64(size, PAGE_SIZE); + if (npgs > U32_MAX) + return -EINVAL; + chunks = (unsigned int)div_u64(size, chunk_size); if (chunks == 0) return -EINVAL; @@ -391,7 +395,7 @@ static int xdp_umem_reg(struct xdp_umem umem->size = size; umem->headroom = headroom; umem->chunk_size_nohr = chunk_size - headroom; - umem->npgs = size / PAGE_SIZE; + umem->npgs = (u32)npgs; umem->pgs = NULL; umem->user = NULL; umem->flags = mr->flags;
Powered by blists - more mailing lists